security: CredentialsChecker is now CredentialsStrategy

and provides encryption too, not just checking.
jongo: security: ease jongo based user repository implementation

restx-jongo now provides a basic UserRepository implementation, which makes
implementing UserManagement in a jongo based app easier.
shell: isolate credentials strategy from the rest in generated AppModule
specs: avoid using specific factories to improve perf

 context locals specific to these factories where not used anyway,
 reusing Factory.getInstance() avoid creating many factories and thus improve perfs
factory: improve perf of checkActive

factory querying has been slowed down a lot since the introduction of activation keys.
improve perf to get back to something close to what it was before this feature was introduced.
core: add timing info on per request factory instanciation

this may be the cause of perf bottlenecks in non prod mode, it's interesting to have some
data about it.
monitor: register metrics only in dev and prod mode

we don't need them in recording / test / infinirest modes, where they don't make much sense
infinirest: improve UI: better results display + play button to run a test manually